This is a fairly simple and really useful idea from the good folks at google. Create a home page where you can see all of your favorite stuff (including several of the things described above) on one web page. I have this set as my home page and it is the first thing I look at in the morning and the last thing I look at before going to bed. I can see what's going on with my calendar, task list (remember the milk), gmail, weather, and rss feeds (google reader) all on one screen.
1. Tons of different gadgets that you can add and arrange on your page.
2. Select a theme to reflect your personality
3. Keep one eye on the news of the day while keeping track of everything else going on in your life.
Science use case:
All of the use cases described above rolled into one easy to use platform